Two-cylinder thick matter pump having a transfer tube

ABSTRACT

A thick matter pump having a material feeding container arranged in which is a pivotable transfer tube. The transfer tube has a pivoting tube that is connected to a delivery line. In order to ensure reliable sealing of the coupling joint between the transfer tube and the container wall, the transfer tube has a metallic ring element which has an inlet in the form of an arcuate slot. A cushion is arranged between the ring element and the pivoting tube. The cushion has an aperture which encloses the slot. The ring element can be moved axially relative to the pivoting tube so that the ring element can be pressed against the inner surface of the container wall via the cushion element under the action of the delivery pressure in the transfer tube.

RELATED APPLICATIONS

This application is a continuation of PCT/EP2014/058291, filed Apr. 24, 2014, which claims priority to DE 10 2013 215 990.0, filed Aug. 13, 2013, both of which are hereby incorporated herein by reference in their entireties.

BACKGROUND

The invention relates to a thick matter pump having a material feeding container and two delivery cylinders which are connected to in each case one orifice opening in the container wall by way of end-side orifice openings, which can be connected alternately to the interior of the container and a delivery line by way of a transfer tube which is arranged in the interior of the material feeding container, the delivery pistons of the delivery cylinders alternately performing a filling stroke and a delivery stroke. It is thus known that the transfer tube has an inlet opening which points in the direction to the orifice openings, is configured as an arcuately curved slot, the width of which inlet opening corresponds to the diameter and the length of which inlet opening corresponds to the outer spacing of the orifice openings, and which has in each case one closure attachment which protrudes beyond the outer edge of the inlet opening in the pivoting direction, the longitudinal extent of which corresponds to the distance between the orifice openings (DE-195 03 986 A1).

The known thick matter pump is characterized in particular in that the inlet opening configured as a curved slot and the two closure attachments for the transfer tube make sure that short-circuiting of the two delivery cylinders is caused, at least occasionally, during the pivoting or switching operation of the transfer tube. These measures ensure that, during the switching operation of the transfer tube, both of the delivery cylinders are separated occasionally from the interior of the material feeding container and can be short-circuited with one another while they are jointly connected to the delivery line, so that one delivery piston is able to complete its delivery stroke and, at the same time, the other delivery piston can already commence its delivery stroke. The delivery piston completing the delivery stroke will not perform its subsequent filling stroke until the short-circuit between the two orifice openings has been discontinued once more and the associated delivery cylinder has been connected to the interior of the container. It is necessary for a reliable function for the transfer tube to be sealed securely against the container wall in the region of the passage openings, both during delivery operation and during switching operation. The known thick matter pump of the kind indicated by way of introduction leaves much to be desired, however, from a sealing technology point of view.

SUMMARY

On this basis, the thick matter pump taught by this disclosure improves the known thick matter pump of the kind indicated by way of introduction in such a way that, both in the stationary state and in the moving state of the transfer tube, adequate sealing is assured in the region of the dividing point between the transfer tube and the container wall.

The solution according to this disclosure resides essentially in the fact that the transfer tube has a metallic ring element, which has the arcuate slot, and a cushion element, which is arranged between the ring element and a pivoting tube, which is connected to the delivery line on the output side and has an aperture which comprises the slot, wherein the ring element is capable of being displaced axially relative to the pivoting tube and of being pressed against the inner surface of the container wall via the cushion element under the action of the delivery pressure in the transfer tube. The measures according to this disclosure ensure that the sealing effect is maintained not only statically in the step position of the transfer tube, but also during the rotating movement of the transfer tube. The transfer tube in this case is reliably sealed in relation to the interior of the container in all switching and operating states. This also applies to the region of the closure attachments, since the cushion element projects into these and produces a pressing action there originating from the interior of the pipe. It should be noted in this case that the closure attachments permit the pre-compression of the thick matter in the course of the switching process at the start of a delivery stroke. According to this disclosure, the cushion element has a non-circular, two-dimensional cross section form. The preferably flexible rubber material behaves in a virtually incompressible manner, similarly to a liquid, which transmits the hydraulic pressure uniformly in all directions. This means that the pressure of the material being conveyed from the interior of the transfer tube is ideally propagated uniformly over the cushion element and, to be precise, into the closure attachments. This causes the metallic ring element to be pressed against the internal surface of the container wall, although only the inlet contour of the cushion element is in contact with the pressurized conveying medium. A further improvement in this respect can be achieved by the provision inside the cushion element of a kind of fluid pocket or gel pocket, via which the pressure can be transmitted even more effectively.

According to a further advantageous embodiment of this disclosure, the container wall on its internal surface facing towards the ring element carries a replaceable wear plate provided with the passage openings. This is capable of being replaced relatively easily in the event of wear. In addition, a material that is more wear-resistant in relation to the material container and is thus more expensive can be used for this purpose.

A further advantageous embodiment of this disclosure proposes that the ring element has a stepped molded pocket intended to receive the cushion element arranged on the pivoting tube side and adapted to the cushion element via its external contour. A further improvement in this respect is achieved if the ring element is also delimited in the direction of the slot by a stepped pocket wall, the height of which is smaller than the outer pocket edge. These measures ensure that the cushion element is embedded securely between the pivoting tube and the ring element, and that it is also not sucked out of its pocket when a suction pressure occurs, which is the case in the course of a flushing operation, for example.

A further improvement in the positioning of the ring element on the pivoting tube is achieved in that a limited elevation of arcuate form and penetrated by a pivoting tube channel is arranged on the cylinder end of the pivoting tube, which elevation has an external contour corresponding to the pocket in the ring element.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned aspects of exemplary embodiments will become more apparent and will be better understood by reference to the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

FIG. 1 depicts a diagrammatic representation of a two-cylinder thick matter pump;

FIG. 2 depicts a representation in principle of the essential parts of the thick matter pump in a diagrammatic exploded view;

FIGS. 3a and b depict two diagrammatic exploded views of the transfer tube with a wear plate observed from various sides;

FIG. 4a depicts the transfer tube with a wear plate in the assembled state of the transfer tube in a representation according to FIG. 3 a;

FIG. 4b depicts a representation according to FIG. 4a with a partially opened transfer tube;

FIGS. 5a to c depict an embodiment viewed from the opposite direction of the ring element with the cushion element in a view from above, a sectioned view and a diagrammatic exploded view.

DESCRIPTION

The embodiments described below are not intended to be exhaustive or to limit the invention to the precise forms disclosed in the following description. Rather, the embodiments are chosen and described so that others skilled in the art may appreciate and understand the principles and practices of this disclosure.

The thick matter pump depicted in FIG. 1 has a material feeding container 10 intended to receive thick matter, such as liquid concrete. The liquid concrete is conveyed into a delivery line 14, only represented in outline here, via a pipe elbow 12. This takes place by means of two delivery cylinders 16, 17, which are connected in each case to a passage opening 18′, 19′ in the container wall 20 by way of end-side orifice openings 18, 19, the delivery pistons 22, 23 of the delivery cylinders alternately performing a filling stroke and a delivery stroke. Present in the interior of the material feeding container 10 is a transfer tube 24, via which the delivery cylinders 16, 17 can be connected alternately to the interior of the container 21 and the delivery line 14. The transfer tube 24 in this case is capable of being caused to pivot by means of a hydraulic drive mechanism respectively into its desired position in relation to the orifice openings 18, 19. The delivery pistons 22, 23 are displaced by means of hydraulic cylinder/piston units 26, 27, of which only the cylinders are indicated schematically in FIG. 1. As explained in greater detail below, the transfer tube 24 has an inlet opening, configured as an arcuately curved slot 28, which points in the direction of the orifice openings 18, 19, the width of which inlet opening corresponds to the diameter and the length of which inlet opening corresponds to the outer spacing of the orifice openings 18, 19, which in each case have one closure attachment 30, 31 which protrudes beyond the outer edge of the slot 28 in the pivoting direction, and the longitudinal extent of which corresponds approximately to the spacing between the orifice openings 18, 19.

A characterizing feature of this disclosure is that the transfer tube has a metallic ring element 32, which has the arcuate slot 28, and a cushion element 36, which is arranged between the ring element 32 and a pivoting tube 34, which is connected to the delivery line on the output side. The cushion element 36 has an aperture 38 which encloses the slot 28 in the ring element 32. The ring element 32 in this case can be displaced axially relative to the pivoting tube 34 and can be pressed against the inner surface of the container wall 20 via the ring element 32 under the action of the delivery pressure generated in the transfer tube 24 in the course of the delivery stroke. The container wall 20 on its internal surface facing towards the ring element 32 carries a replaceable metallic wear plate 20′ provided with the passage openings 18′, 19′ and with a bearing bore 40 for the bearing pins 42.

As can be appreciated from FIGS. 5a to 5c , the ring element 32 has a stepped molded pocket 44 intended to receive the cushion element 36 arranged on the pivoting tube side, adapted to the cushion element 36 via its external contour. In this illustrative embodiment, the ring element 32 is also delimited in the direction of the slot 28 by a stepped inner pocket wall 46, the height of which is smaller than the outer pocket edge 48. Present on the cylinder end of the pivoting tube 34 is a limited elevation 50 of arcuate form, which elevation is penetrated by the pivoting tube channel 52 (FIG. 3a ) and has an external contour (FIG. 3b ) corresponding to the pocket 44 in the ring element 32. The axial guidance of the ring element 32 on the pivoting tube 34 is improved and stabilized with these measures.

In order to ensure the reliable transfer of pressure, the cushion element 36 consists of a pliable, elastic or flexible rubber material. A further improvement in the pressing action can be achieved in that the cushion element 36 contains a filling constituted as an incompressible fluid.

The inlet opening of the transfer tube or the ring element is conceived in such a way with its curved slot form that the two delivery cylinders 16, 17 are short-circuited via their orifice openings 18, 19 inside the slot 28. A smooth, jolt-free switching process can be assured if both of the delivery cylinders 16, 17 in this position execute a delivery stroke with their delivery pistons 22, 23. In order to prepare for the switching process, an initial pressure can be built up in the previously filled delivery cylinder already during the transfer of the closure attachment 30, 31 to the transfer tube 24. A further improvement in respect of the continuous flow through the delivery line is achieved as a result, including during the switching operation. On the other hand, this means that the piston speed, and with it the duration of the stroke, are different during the filling stroke and the delivery stroke, since less time is available for the filling stroke than for the delivery stroke as a consequence of the functional characterizing features described here.

In summary, it can be established that this disclosure relates to a thick matter pump having a material feeding container 10 and two delivery cylinders 16, 17 which are connected to in each case one passage opening 18′, 19′ in the container wall 20 by way of end-side orifice openings 18, 19. The delivery cylinders 16, 17 are connected alternately to the interior of the container 21 and a delivery line 14 by way of a transfer tube 24 which is arranged in the interior of the material feeding container 10, whereas the delivery pistons 22, 23 of the delivery cylinders alternately perform a filling stroke and a delivery stroke. The transfer tube 24 has an inlet opening which points in the direction of the orifice openings 18, 19, is configured as an arcuately curved slot 28, the width of which corresponds to the diameter and the length of which corresponds to the outer spacing of the orifice openings 18, 19, which have in each case one closure attachment 30, 31 which protrudes beyond the outer edge of the slot in the pivoting direction, and the longitudinal extent of which corresponds to the spacing between the orifice openings. In order to ensure reliable sealing of the coupling joint between the transfer tube 24 and the container wall 20, it is proposed according to this disclosure that the transfer tube 24 has a metallic ring element 32, which has the arcuate slot 28, and a cushion element 36, which is arranged between the ring element 32 and a pivoting tube 34, which is connected to the delivery line 14 on the output side, and has an aperture 38 which encloses the slot 28, wherein the ring element 32 is capable of being displaced axially relative to the pivoting tube 34 and of being pressed against the inner surface of the container wall via the cushion element 36 under the action of the delivery pressure in the transfer tube 24.

While exemplary embodiments have been disclosed hereinabove, the present invention is not limited to the disclosed embodiments. Instead, this application is intended to cover any variations, uses, or adaptations of this disclosure using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.

LIST OF REFERENCE DESIGNATIONS

-   10 material feeding container -   12 pipe elbow -   14 delivery line -   16,17 delivery cylinders -   18,19 orifice openings -   18′,19′ passage openings -   20 container wall -   20′ wear plate -   21 interior of the container -   22,23 delivery pistons -   24 transfer tube -   26,27 cylinder/piston units -   28 slot -   30,31 closure attachment -   32 ring element -   34 pivoting tube -   36 cushion element -   38 aperture -   40 bearing bore -   42 bearing pin -   44 pocket -   46 pocket wall -   48 pocket edge -   50 elevation -   52 pivoting tube channel 

What is claimed is:
 1. A thick matter pump, comprising: a material feeding container having an interior and a container wall, the container wall having first and second passage openings; a first delivery cylinder fluidly connected to the first passage opening and having a first piston and a first orifice, and a second delivery cylinder fluidly connected to the second passage opening and having a second piston and a second orifice, the first and second pistons alternately performing filling and delivery strokes; a transfer tube arranged in the interior of the material feeding container and being pivotable in a pivot direction, the transfer tube having a pivoting tube extending therefrom and connected to a delivery line, the transfer tube configured to alternately connect the first and second delivery cylinders to the interior of the container and the delivery line; a metallic ring element arranged about the transfer tube, the metallic ring element comprising an inlet oriented in the direction of the first and second orifices and configured as an arcuate slot, the inlet having a width corresponding to the diameter of the passage openings and having a length corresponding to an outer spacing of the passage openings, the metallic ring element further comprising first and second closure attachments associated with the first and second passage openings, respectively, the closure attachments protruding beyond an outer edge of the arcuate slot in the pivoting direction; and a cushion arranged between the ring element and the pivoting tube, the cushion having an aperture enclosing the arcuate slot, wherein the ring element is axially displaceable relative to the pivoting tube to press against the inner surface of the container wall via the cushion element under the action of delivery pressure in the transfer tube.
 2. The thick matter pump as claimed in claim 1, wherein the container wall on an internal surface facing towards the ring element carries a replaceable wear plate provided with the first and second passage openings.
 3. The thick matter pump as claimed in claim 1, wherein the ring element has a stepped molded pocket configured to receive the cushion, the molded pocket having an external contour corresponding to the cushion and forming an outer pocket edge.
 4. The thick matter pump as claimed in claim 3, wherein the ring element is delimited in the direction of the slot by a stepped pocket wall having a height which is smaller than the outer pocket edge.
 5. The thick matter pump as claimed in claim 3, wherein an elevation of limited arcuate form and penetrated by a pivoting tube channel is arranged on a cylinder end of the pivoting tube, the elevation having an external contour corresponding to the pocket in the ring element.
 6. The thick matter pump as claimed in claim 1, wherein the cushion is a pliable or elastic material.
 7. The thick matter pump as claimed in claim 1, wherein the cushion comprises a flexible rubber material.
 8. The thick matter pump as claimed in claim 1, wherein the cushion contains an incompressible fluid. 